The Cardiac Cycle Flashcards
What is the most important part of the ECG when diagnosing an acute MI?
The ST segment.
What does the ST segment represent?
Represents the interval between ventricular depolarization and repolarization.
The most important cause of ST segment abnormality (elevation or depression) is myocardial ischaemia or infarction.
What is ST Elevation?
What does it indicate?
When the ST Segment is above the baseline voltage.
Indicates an MI (ST-Elevation Myocardial Infarction (STEMI)) - a very serious type of heart attack during which one of the heart’s major arteries is blocked
What heart protein is used to diagnose an MI?
Troponin.
Regulatory proteins within the myocardium that are released into the circulation when damage to the myocyte has occurred.
Therefore, serum troponins are a sensitive marker of myocardial injury and is necessary for establishing the diagnosis of MI.
What is this?
An atherosclerotic plaque.
What is the coronary flow reserve?
The ratio of blood flow at rest and the max. blood flow of the vascular (maximally dialated)
The maximum amount of blood flow that your heart can sustain
Why may you become short of breath when having a heart attack?
As blood flow slows and backs up into the pulmonary veins, pressure increases.
Fluid is squeezed out and fill the alveoli, reducing lung capacity.
Pulmonary oedema.
What does a stable atherosclerosis look like?
Left side is a stable atherosclerosis.
Core of cholesterol which is liquid at room temperature.
Separated from the lumen by a very thick fibrous cap.
What is the most affective prevention of atherosclerosis build up?
Decrease your LDL cholesterol.
Using statins.
What is Tissue plasminogen activator (tPA)?
A protein involved in the breakdown of blood clots.
An enzyme, it catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown.
Administered during ischemic stroke / MI.
What is mechanical reperfusion?
(and how does it compare to pharmological reperfusion?
The use of a stent to open up a block artery.
Clot is mechanically disrupted with a wire stent.
- Faster reperfusion.
- Higher % reperfusion.
- Less stroke and bleeds.
- Lower mortality
(compared to pharmalogical reperfusion)
What are the two types of MI?
(and how are they discerned)
ST elevation MI (STEMI)
Non-ST elevation MI (NSTEMI)
Discerned by the ECG appearance.
What are the three stages to diagnose a myocardial infarction?
- Immediate ECG.
-
Troponin release (4-12hrs).
- will get lab result back within an hour
- Late ECG (12-72hrs).
What does the diagnosis of an MI require?
A posiitve troponin blood test.
What are the ‘big five’ classes of drugs to treat MIs?
And give an example of each drug.
- Statins (Atorvastatin),
- ACE inhibitor (Ramipril),
- Beta-blocker (Bisoprolol),
- Aspirin – to prevent blood clots,
- Antiplatelet (Ticagrelor),
What can happen to the heart if the muscular walls have thinned?
Heart dilation
